Such a headlight lamp is disclosed, for example, in German Laid-open Patent Application DE 199 51 203 A1. This patent application describes a headlight lamp having a lamp vessel, an incandescent filament enclosed therein, and a lamp base which is provided with the electric terminals of the headlight lamp. The lamp base has an annular metallic holder for anchoring the lamp vessel. Moreover, the lamp base has three reference noses arranged in a common plane, and an annular base flange, the base flange plane being arranged parallel to the plane of the reference noses. The base flange is provided with three lugs of resilient design which are arranged along its circumference and serve together with the reference noses for fastening the lamp in a headlight. Owing to the adjustment of the incandescent filament with reference to the reference noses, when the base is being mounted undesired slots or openings can result in the lamp base, and so dust can penetrate into the lamp base.